Name
APPLE_texture_max_level
Name Strings
GL_APPLE_texture_max_level
Contributors
Contributors to SGIS_texture_lod desktop OpenGL extension from which
this extension borrows heavily.
Contacts
Benj Lipchak, Apple (lipchak 'at' apple.com)
Status
Complete
Version
Last Modified Date: February 24, 2011
Revision: #2
Number
OpenGL ES Extension #80
Dependencies
Written based on the wording of the OpenGL ES 2.0 specification.
OpenGL ES 1.1 affects the definition of this extension.
Overview
This extension allows an application to specify the maximum (coarsest)
mipmap level that may be selected for the specified texture. This maximum
level is also used to determine which mip levels are considered when
determining texture completeness.
IP Status
No known IP claims.
New Procedures and Functions
None
New Tokens
Accepted by the parameter of TexParameteri, TexParameterf,
TexParameteriv, TexParameterfv, GetTexParameteriv, and GetTexParameterfv:
TEXTURE_MAX_LEVEL_APPLE 0x813D
Additions to Chapter 2 of the OpenGL ES 2.0 Specification (OpenGL Operation)
None
Additions to Chapter 3 of the OpenGL ES 2.0 Specification (Rasterization)
Add the following line to Table 3.10 (Texture parameters and their values):
Name Type Legal Values
---- ---- ------------
TEXTURE_MAX_LEVEL_APPLE integer any non-negative integer
In section 3.7.4, insert the following paragraph before the paragraph
beginning "Texture parameters for a cube map texture...":
"In the remainder of section 3.7, denote by level_max the value of the
texture parameter TEXTURE_MAX_LEVEL_APPLE."
In section 3.7.7 subsection "Mipmapping" modify the second paragraph
such that p and q are defined as follows:
p = floor(log2(max(w_b, h_b)))
q = min{p, level_max}
In section 3.7.7 subsection "Mipmapping" insert the following paragraph
before the paragraph beginning "The mipmap is used in conjunction...":
"The value of level_max may be respecified for a specific texture by
calling TexParameter[if] with set to TEXTURE_MAX_LEVEL_APPLE.
The error INVALID_VALUE is generated if the specified value is negative."
In section 3.7.12, modify the last three sentences to read as follows:
"Next, there are the two sets of texture properties; each consists of the
selected minification and magnification filters, the maximum array level,
and the wrap modes for s and t. In the initial state, the value assigned
to TEXTURE_MIN_FILTER is NEAREST_MIPMAP_LINEAR, and the value for
TEXTURE_MAG_FILTER is LINEAR. s and t wrap modes are both set to REPEAT.
The value of TEXTURE_MAX_LEVEL_APPLE is 1000."
Additions to Chapter 4 of the OpenGL ES 2.0 Specification (Per-Fragment
Operations and the Frame Buffer)
None
Additions to Chapter 5 of the OpenGL ES 2.0 Specification (Special Functions)
None
Additions to Chapter 6 of the OpenGL ES 2.0 Specification (State and State
Requests)
None
Dependencies on OpenGL ES 1.1
On an OpenGL ES 1.1 implementation, include fixed-point flavors of
TexParameter and GetTexParameter commands.
Errors
INVALID_VALUE is generated if an attempt is made to set
TEXTURE_MAX_LEVEL_APPLE to a negative value.
New State
Add the following to Table 6.8 (Textures (state per texture object):
Initial
Get Value Get Command Type Value Description Sec.
--------- ----------------- ------ ------- ----------- ----
TEXTURE_MAX_LEVEL_APPLE GetTexParameteriv n x Z+ 1000 Maximum texture 3.7
array level
New Implementation Dependent State
None
Revision History
#2 02/24/2011 Benj Lipchak Assign extension number
#1 10/29/2009 Benj Lipchak First draft